How is the angular app deployed?
Inside a Plone package or separate as static website in apache/nginx?
In Angular & co you can define a base url/path and use it for static files, so it should not be a problem how the url's look. In other systems they are more ugly anyway ;).
You would than access all url's inside your app like /static/my-file.rtf and the routing of Angular knows where to go in the backend for file in /static path.